R Visualizations: Flow Charts in R

part of my “taking advantage of R visualizations” blog series

Photo by Cris DiNoto on Unsplash

Photo by Cris DiNoto on Unsplash

Introduction

In the field of data analytics, data visualization is the name of the game. I have recently noticed how much I love R over Python for my data visualization needs. Because of this, I have started a small blog series on R visualizations beginning with this blog on flow charts. you can find the blog on my medium.

# install.packages("DiagrammeR") # used to install the package dependencies needed for this blog
library(DiagrammeR)

Once the library has loaded, we will use the grViz() function to setup the bones of our flow chart.

grViz(diagram = "digraph flowchart {
  node [fontname = arial, shape = oval]
  tab1 [label = '@@1']
  tab2 [label = '@@2']
  tab3 [label = '@@3']
  
  tab1 -> tab2 -> tab3;
}
  
  [1]: 'Learning Data Science'
  [2]: 'Industry vs Technical Knowledge'    
  [3]: 'Statistics vs Mathematics Knowledge'    
  ")

Within the syntax,

Adding Color

It is also possible to add color to the outline of your nodes, or even fill them with a color. To do so, add additional arguments “color” and “style” to the node section of the syntax as shown below.

grViz(diagram = "digraph flowchart {
  node [fontname = arial, shape = oval, color = grey, style = filled]
  tab1 [label = '@@1']
  tab2 [label = '@@2']
  tab3 [label = '@@3']
  
  tab1 -> tab2 -> tab3;
}
  
  [1]: 'Learning Data Science'
  [2]: 'Industry vs Technical Knowledge'    
  [3]: 'Statistics vs Mathematics Knowledge'    
  ")

Splitting Connection to Multiple Nodes

You are able to split the connection to multiple nodes. To do so just change how your structure your tab argument.

grViz(diagram = "digraph flowchart {
      # define node aesthetics
      node [fontname = Arial, shape = oval, color = Lavender, style = filled]        
      tab1 [label = '@@1']
      tab2 [label = '@@2']
      tab3 [label = '@@3']
      tab4 [label = '@@4']

      # set up node layout
      tab1 -> tab2;
      tab2 -> tab3;
      tab2 -> tab4
      }

      [1]: 'Learning Data Science'
      [2]: 'Industry vs Technical Knowledge'
      [3]: 'Python/R'
      [4]: 'Domain Experience'
      ")

More Customizability

There are some additional arguments you can include in your function to customize things such as font size, font color, height, width, alpha, etc… For more customizability options refer to the documentation Once you have selected the styles or additions you want, add them as arguments within the node[] portion of your function.

grViz(diagram = "digraph flowchart {
      # define node aesthetics
      node [fontname = Arial, shape = oval, color = DeepSkyBlue, style = filled, fontcolor = White]        
      tab1 [label = '@@1']
      tab2 [label = '@@2']
      tab3 [label = '@@3']
      tab4 [label = '@@4']

      # set up node layout
      tab1 -> tab2;
      tab2 -> tab3;
      tab2 -> tab4
      }

      [1]: 'Learning Data Science'
      [2]: 'Industry vs Technical Knowledge'
      [3]: 'Python/R'
      [4]: 'Domain Experience'
      ")

Conclusion

Flow charts are a great way to express ideas especially at the beginning stages of production. Consider using R visualizations in your future work and take advantage of its powerful libraries.